The Kansas University science bulletin, Vol. I, No. 8, September 1902 — John Shaqi
The Kansas University science bulletin, Vol. I, No. 8, September 1902
Science
The Kansas University science bulletin, Vol. I, No. 8, September 1902
Science -- Periodicals
In reply to my previous objection directed against this part of his
work, Montgomery acknowledges the validity of the criticism so far as it
relates to the metaphase, but denies the application to the other
phases, particularly to the anaphase. He alleges in support of his
position that the introduction of an unusual condition, the “synapsis,”
makes it impossible to correlate strictly the stages of the germ-cells
with those of ordinary divisions. Upon this point I must again disagree
with him. It is impossible for any known modification of the prophase to
change the essential character of the anaphase, so as to make it precede
instead of follow the metaphase. This stage marks the movements of the
chromosomes from the equatorial plate to the poles, and terminates when
they are massed around the centrosomes. How can the “synapsis” in the
least affect the duration or character of this process? It is apparent
enough, I think, that Montgomery’s subphases of the “anaphase” do not
belong to this portion of the mitotic cycle at all, but are really
portions of the telophase of the spermatogonia and prophase of the first
spermatocyte. Further, it may be noted that, even were these subphases
properly included in the anaphase, they would belong to the
spermatogonia and not to the spermatocytes.
Montgomery himself seems to be rather uncertain of the position of his
“anaphase.” In the first paper, upon _Euchistus_ (=12=), it was put down
as the anaphase of the first spermatocyte; in his later paper (=14=),
upon _Peripatus_, it is recorded as the anaphase of the spermatogonia.
Still more confusing is his use of the “telophases,” for in the article
upon _Peripatus_ (=14=) it is, in the “Contents,” placed as a substage
of the spermatogonial anaphase, and in the body of the work, page 307,
as the telophase of the spermatocyte! Neither the anaphase nor the
telophase can, by any possible construction of their proper meanings, be
made to apply to the “growth period” of the germ cycle, as Montgomery
insists; they are the last stages of the “division period,” in reality.
The prophase of the first spermatocyte is the initial stage in the
constructive process marking the growth period.
Public-domain text, read in full here on John Shaqi.
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